Pure typing list of effects

Normal: General Physical Improvement. Ie: Longer lifespan, better physical strength than average, better appearance, etc. No real downside, except all of the effects are more moderate than the others.

Fire: Temperature Control/ Heat resistance. Some people might have Pyrokinesis. Downside is lowered body temperature and becomes more susceptible to cold weather.

Water: Able to hold breathe for longer. This can become closer to Kevin Costner from Waterworld for some people, ie people with gills and webbed fingers and toes. Downside is that the later effects WILL happen. It's only a matter of time.

Grass: "Growth field" Plants near to or cared for by the trainer will grow faster and turn out better. Downside, you become Solar Powered.

Electric: Probably the most subtle one from the original typing. For most people it's essentially the Bullet Time ability. However, it generally speeds up the electrical synapses of the trainer's nervous system. Downside, possible Sensory Overload. One kick to the nuts might actually kill you.

Ice: Generally the exact opposite of Fire. Temperature Control/Cold Resistance and some people might have an Cryokinesis. However, hot temperatures are bad for you, and your natural body temperature is higher.

Fighting: Increased muscle density. Basically normal level of mass, but the muscles become more capable. Some people would develop a basic ability to harness Aura. Downside, increased Metabolism.

Poison: Dependent on Pokemon. If you have more pokemon like Koffing, Muk, and the Oddish line, you get Poison Resistance. However, if you get the Zubat Line, Seviper, or the Ekans line, you get Venom Resistance. Remember, if it bites you and you die, it's venomous. If you bite it and you die, it's poisonous. Downside, need a good mix to have an actual resistance to both venom and poison.

Ground: Skin becomes harder. Some people might develop abilities that include things like Sand control, etc. Downside is your skin becomes less sensitive. This is across the board, so you might grab your cup to drink your water, and you shatter the glass.

Flying: You become lighter, and your bones become hollow. Some people develop wing flaps under their arms. Downside: bone breaks are more painful and more expensive because your bones are hollow.

Psychic: Telepathy for most, add in telekinesis for some. Add in other psychic abilities for some more. Downside: Susceptible to other Psychics. Normal people can't be targeted by most psychics because it takes a lot more power to do so. Also most psychics tend to develop OCD.

Bug: Depends on what pokemon the trainers own. After all, trainers with Ariados or Galvantula get to act like Spider man. Downside: Typically shorter lifespan.

Rock: Bit of strength, skin is a bit harder than normal. Downside: Decreased sensitivity, and increased weight.

Ghost: Normally ghost would be a "life" sense. Literally telling if there is anything alive within a certain range. Some people get the whole Phasing through walls thing. But it's extremely rare. Downside: Generally prefer darker settings. After a certain point, sunlight actually becomes immediately harmful.

Dragon: Longer life span. Some people get the ability to manipulate dragon energy as well. Downside: the Reverse Scale. There is one location that will instantly at least knock you out. And you don't know where that is.

Dark, Steel, and Fairy are actually discovered yet in this world, though the traits are listed here.

Dark: Immunity to Telepathy and other psychic abilities. Some people develop shadow control or the basic ninja Downside: Aura abilities are even stronger against you. Also you give off a feeling of untrustworthiness.

Steel: Harder skin, to the point where your skin actually becomes as tough as metal. Some people get some level of metal control. Also a significant increase to strength. Downside: Massive increase to weight. Hundred pound person would actually weigh closer to five hundred. Most of the strength bonus is just so regular people can walk around.

Fairy: Varies based on person. Some people get some minor changes to appearance, while others get some kind of outlandish abilities. If you think about the Seelie and Unseelie Courts, your not far wrong. Downside: No two people are alike, so you have to figure out your talents on your own.

This is the basic list so people will have an idea for what some of the people later are kind of going through. I'm mostly talking about the gym leaders as well. However certain characters will purposefully have abilities that make sense for them. Ex: Jasmine doesn't weigh an exceptionally high weight. However, she is slightly magnetic. Certain pokemon will actually stick to her, and she can literally attach her pokeballs to her with no other devices assistance.